1. Field of the Invention
This invention relates to troubleshooting. Specifically, the present invention relates to cable troubleshooting.
2. Description of the Related Art
Utility companies provide service to customers. Whether the Utili8ty Company is a power company or a communications company, the Utility Company uses a utility conveyance to provide the service to customers. A utility conveyance typically includes the cables and mechanisms for transporting the Utility Company service to customers.
Cabling is a widely deployed mechanism (e.g., utility conveyance) for transporting Utility Company services. For example, copper cabling, coaxial cabling and fiber-optic cabling are all common types of cabling used to deploy services. The cabling typically spans the distance from the source to the destination (e.g., customer).
The cabling is often placed in locations that are unobtrusive so that the likelihood of damage to the cable is minimized and as a result, service is not disrupted. Therefore, cables are often placed in subterranean locations as well as locations above the earth for protection from damage. For example, cables are often run in trenches or cables are strung many feet (e.g., 15–50) above the earth between support poles.
However, whether the cables are placed in a subterranean environment or strung between support poles, the cables are still subject to activities that may damage the cables. For example, when cables are strung between support poles, lightening may strike the cables, high winds may damage the cables, or a hailstorm may cause damage. When these cables are damaged, they need to be fixed to avoid or minimize a disruption in service.
Service technicians are typically dispatched to isolate and repair the cable damage. Whether the cables are in a subterranean environment or strung between support poles, the technicians first isolate the fault in the damaged cable and then proceed with the cable repair. For example, if communication cable carrying optical fibers are strung between poles, a technician would first need to isolate the fault in the outer sheath of the cable and then proceed to repair the optical fibers.
However, a number of problems arise when a technician attempts to isolate a fault in a cable that is strung between support poles. For example, since the cable is about 25 to 30 feet above the earth it is difficult to see the faults in these cables from the ground. In addition, even if the technician were to climb the support pole to view the damaged cable, since the poles are positioned a certain distance apart, it may be difficult to see the fault after climbing the poles.
A number of conventional techniques have been developed to isolate and more accurately define the location of damage or faults in cables strung between support poles. For example, when fiber optic cable is strung between support poles, an Optical Time-Domain Reflectometer (OTDR) may be used to more accurately locate the fault in the cable. The OTDR may isolate the fault to a location between two support poles.
However, even with a technique that isolates the location of a fault, problems arise. First, the OTDR may not have a fine calibration and as such the fault may be isolated to a span of cable that is tens of feet long. Second, in order to troubleshoot the fault the technician must see the fault. However, it is difficult to see the fault from the ground. Even using binoculars it is difficult to steady the human hand enough to isolate and see the fault. In addition, depending on where the fault is located between two support poles, it may be difficult to see the fault from either pole. Lastly, taking the cable down or bringing in machinery to reach the cable when the fault has not been isolated can result in tremendous cost if the technician has identified the wrong stretch of cable.
Thus, there is a need in the art for a method and apparatus for isolating faults in cables that are strung between support poles. There is a need in the art for a method and apparatus for viewing faults in cables that are strung between support poles. There is a need in the art for a method and apparatus for isolating and viewing faults in cables that are positioned in locations, which are difficult to access.